The instant invention relates to a compression molded panel and specifically to the treatment of a compression molded panel to yield a water proof, single piece, structurally strong storm door core or panel that has the strength and feel of solid wood but is instead made from a wood fiber or wood chip board, preferably of a low initial density.
The applicant knows of no prior art which teaches the unique features and designs of his invention. For example, U.S. Pat. No. 4,007,569 (Hascall), discloses a method for sealing the edges of an exterior wooden door by overlaying a thin, vinyl plastic tape over the edge of the door and bonding the tape with an adhesive. U.S. Pat. No. 4,146,662 (Eggers, et al), discloses a warp and weather resistant solid core wood door having an overlaid laminate of phenolic resin-impregnated paper and veneer bonded in a heated press to the front and rear surfaces of a core material such as particle board. No single piece compressible resin impregnated structure like that of the instant invention is shown or described. U.S. Pat. No. 4,236,365 (Wheeler), describes a door formed from a core of compressed wooden particles mixed with an adhesive in a heated press. The door is provided with a solid wooden edge frame and high density exterior of cellulosic fibers. The door may be embossed on one or both exterior surfaces to provide a decorative panel pattern. The structure of the Wheeler door is made up of wood particles that are compressed between two high density skins 14 and 16. Again, single piece construction like that of the instant invention is not disclosed, and applicant's unique way of achieving sharp molding profiles is not disclosed either.
U.S. Pat. No. 4,610,119 (Bench, Sr.), discloses a laminated exterior door having two poly-carbonate sheets adhesively bonded to a composite wooden substrate or core of solid fiberboard. The adhesive consists of a moisture curing urethane that remains somewhat tacky after bonding. This is not the structure or method of the instant invention. U.S. Pat. No. 3,334,464 (Charles) discloses a door comprising more than one layer of material surrounding a plastic foam core. U.S. Pat. No. 4,630,420 (Hagemeyer) discloses a thermal and moisture resistant door comprising a perimeter framework with a laminated skin glued to the interior and exterior sides of the framework, with an insulative core material therebetween. This structure is completely counter to the one piece panel construction and structure disclosed hereafter by the applicants. U.S. Pat. No. 4,812,188 (Hanson) merely discloses a method of producing doors or other panel elements with the appearance of an infilled panel type; the panelling pattern achieved through a simple relief pressing of a thin covering plate member which is mounted on a carrier frame work. The covering plate member, coated by a veneer or paper, is produced from wood fiber or a chip mass which is pressed and heated only to the extent that the plate material becomes leather-like; without the incorporated binding agent being hardened. By the relief pressing of the covering plate, heat is supplied in such a manner that the binding agent hardens after the final deformation pressure has been applied. Essentially this reference discloses a method of laminating using a very thin chip board base member so that the final product is made up of more than one layer of material; all the layers being bonded together. Accordingly, the instant invention is neither taught nor disclosed. U.S. Pat. No. 4,844,968 (Persson, et al) discloses a heat form pressed product, namely a door skin, and a method of manufacturing such an object. The door skin disclosed comprises a resin impregnated outer layer arranged directly onto a layer of a binder impregnated wood fine chips that act as a support for the fiber sheet material. However, this resin impregnated layer is crepe paper. Crepe paper is very thin and, unlike the wood fiber panel of the instant invention, would lack the necessary strength unless it was bound or laminated to another structure as Persson describes. The apparent purpose of the crepe paper is to produce an acceptable surface quality. The crepe paper alone could not form a door core, siding panel, or the like. A layer of coarse wood chips is disclosed as acting as to define the reinforcing and handling characteristics of the relatively large (some m.sup.2) and relatively thin (2 to 5 mm) door skin. This patent does disclose the use of a resin impregnated layer as one of the layers used in forming the door skin, however the structure and method disclosed are not the same as the structure and method of the applicants which creates a complete door core or panel, not a door skin, out of one layer of compressible wood fiber material. Essentially the Persson patent discloses a laminating process in which a door skin is directly bonded to a layer of wood chips to form a door having depressions or panels. This is completely different from the method and structure of the applicant in which a door core is made from a single compressible wood fiber board impregnated with an unsaturated polyester resin. U.S. Pat. No. 4,864,789 (Thorn) discloses a compression molded door assembly in which no frame is needed because the edges of the opposed door skins include integral mating edge members over at least a portion of the side edges. While the door skins are made from unsaturated polyester polymers blended with vinyl monomers such as styrene, the skins do not form the whole door nor are they made by mixing the polymers with wood fiber board. A filler material that is added to the polymers is disclosed but the function of these fillers is not the same as disclosed herein. The skins are designed to be mounted onto a core; like the foamed core 13 disclosed in the Thorn patent. The structure and method of the applicant is neither suggested nor disclosed. None of the above cited prior art reveals the method or structure of the applicant's unique invention.
It is the primary objective of the present invention to produce a wood fiber or wood chip compressed panel into which plastic resin has been introduced through the surface of the wood fiber board so the resin at least encapsulates the wood material of the board located on the surface of the board and, preferably, at least a slight depth below the surface of the wood board; so that the resin may be fused or set while it encapsulates at least a portion of the wood structure of the board whereby an essentially moisture impervious panel having good strength characteristics is produced. The panel so produced is for use as a door core or any other use, such as outdoor siding, in which a moisture resistant or impervious panel having excellent strength and durability characteristics is desired.
It is an objective of the instant invention to produce a door core product that is preferably 33 percent plastic and 67 percent wood. The strength and flexibility of this product far exceeds particle board which is standard in the wood core business. The product has excellent insulating properties, in that the composition is preferably wood fiber (insulating board) encased or encapsulated on all sides and edges with a layer of plastic. The above characteristics enable the product to provide long term durability.
It is a further objective of this invention to have a method of manufacture produced door cores or panels from compressible wood fiber board that have the strength and aesthetic raised panel or other three dimensional look of machined solid wood cores that are currently available on the market today.
It is another objective of this invention to produce a door core or panel that is superior to particle board laminated cores that are available on the market today. Currently available particle board panels simulate the raised panel design feature by applying plastic or aluminum molded parts which are screwed onto the face of the door. This leaves the wood cores of these doors and panels vulnerable to moisture penetration that will causes the vinyl or aluminum to delaminate. Further, the colors of these added parts must be matched to the color of the door core or panel. The instant invention overcomes these problems by providing a door core or panel that can have an integral design and need little or no extra finishing work performed upon it before shipment.
In the claims and specification of this patent the following terms, in addition to their normal meanings, should be interpreted and understood to have the following meanings:
Impregnate: To penetrate or encapsulate less than all parts of a substance.
Catalyst: 1. One or more polymerization initiating materials capable of initiating polymerization with or without additional heat or pressure. 2. One or more materials capable of causing a resin material to set-up or solidify.
Wood Fiber Board: A substantially solid wood board comprised of wood chips or wood fibers or cellulosic fibers and capable of being compressed.
If there is a contradiction between an above stated meaning of a term and its common meaning, the definition of the term or word will be interpreted as covering both meanings inclusively so as not to exclude one or the other.